IV) Salts, Cocrystals, and Salt

Article pubs.acs.org/crystal

Heterometallic Copper(II)−Tin(II/IV) Salts, Cocrystals, and Salt Cocrystals: Selectivity and Structural Diversity Depending on Ligand Substitution and the Metal Oxidation State Susanta Hazra,*,†,‡ Priyanka Chakraborty,† and Sasankasekhar Mohanta*,† †

Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700 009, India Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049−001, Lisbon, Portugal

‡

S Supporting Information *

ABSTRACT: Two copper metallo-ligands [CuL1(H2O)] and [CuL2⊂(H2O)] [H2L1 = N,N′-ethylenebis(3-methoxysalicylaldimine) and H2L2 = N,N′ethylenebis(3-ethoxysalicylaldimine)] have been utilized for the preparation of heterobimetallic eight CuIISnIV complexes [CuL1]2·[SnMe2Cl4]2−·(H2ED)2+ (1), [CuL1]2·[SnEt2Cl4]2−·(H2ED)2+·0.5H2O (2), [CuL1]2·[Sn(n-Bu)2Cl4]2−· (H2ED)2+ (3), [CuL1]2·[SnPh2Cl4]2−·(H2ED)2+ (4), [CuL1]2·[SnPh2Cl4]2−· (H2ED)2+·2MeOH (5), [CuL2]2·[SnMe2Cl2(H2O)2]·0.2H2O (6), [CuL2]· [Sn(n-Bu)2Cl2(H2O)] (7), [CuL2]2·[SnPh2Cl4]2−·(H2ED)2+ (8), and two CuIISnII systems [CuL1SnCl]+·[SnCl3]− (9) and [CuL2SnCl]+·[SnCl3]− (10) (ED = 1,2-ethylenediamine). Single crystal X-ray structure analyses indicate that 1−5 and 8 are three-component [1×2+1×1+1×1] salt cocrystals of two neutral mononuclear [CuL1]/[CuL2] moieties, one organometallic dianion [SnR2Cl4]2− (R = Me, Et, n-Bu, and Ph), and one doubly protonated 1,2-ethylenediammonium dication H2ED2+, while compounds 6 and 7 are twocomponent [1×2+1×1]/[1×1+1×1] cocrystals of one/two neutral mononuclear [CuL2] and one neutral organotin(IV) moieties. Compounds 9 and 10 are two-component salts which are comprised of heterometallic, diphenoxido-bridged, dinuclear CuIISnII cation [CuLSnCl]+ and SnII anionic residue [SnCl3]−. Interestingly, the formation of the salt cocrystals or cocrystals 1−8 and salts 9 and 10 can be well rationalized in terms of several noncovalent weak interactions (O−H···O/N−H···O/N−H···Cl/ Cu···Cl/Sn···Cl/Sn···Cu/π···π) which result in the generation of a tetrameric associate in 7, one-dimensional topology in 3−5 and 8−10 and two-dimensional supramolecular associate in 1 and 2. The first metallo-ligand [CuL1(H2O)] produces similar three-component CuII···SnIV···diprotonated diamine salt cocrystals (1−5), attesting to the selectivity toward the formation of this type of compound, while the latter one [CuL2⊂(H2O)] displays a diverse structure forming capability by producing a CuII··· SnIV···diprotonated diamine salt cocrystal (8) and two CuII···SnIV cocrystals (6 and 7). Interestingly, no such selectivity is observed for their heterometallic CuIISnII derivatives (9 and 10) which are similar two-component salts and completely different from 1−8. The current study illustrates an excellent example of structural diversity in heterometallic CuIISnII/IV complexes depending on the ligand substitution and metal oxidation state. Moreover, a heterometallic system, such as 1−5 and 8, containing ammonium-stannate adduct (X−NH3·SnX6, X = any) is not known according to the search made on the Cambridge Structural Database (CSD).

■

concerned components are neutral moieties;48−63 (ii) salts where the components are charge balancing opposite ions (although organic acid···organic base pairs are usually socalled);48−53,64−69 and (iii) salt cocrystals where neutral, cationic and anionic components coexist.49−53 The area of multicomponent crystals is dominated by organic systems.34−57 The formation of organic cocrystals can be rationalized in terms of weak interactions, and therefore it has also been possible to design several targeted multicomponent assemblies. In contrast, cocrystals of metal complexes have been not only much less

INTRODUCTION

Although heterometallic systems are of great importance due to the variety in their structural, magnetic, biological, and catalytic properties,1−14 such systems have been much less investigated in comparison to the homometallic compounds. Again, there are some metal ions, e.g., SnII/SnIV, for which heterometallic complexes have been sparsely reported.15−33 Therefore, exploration of syntheses/structures/properties of heterometallic complexes containing SnII/SnIV as a component deserves attention. Multicomponent crystals are important due to their applications as pharmaceuticals,34−39 nonlinear optical materials,40−43 and charge-transfer solids.44−47 There are basically three types of such compounds: (i) cocrystals where all the © XXXX American Chemical Society

Received: February 26, 2016 Revised: April 29, 2016

A

DOI: 10.1021/acs.cgd.6b00321 Cryst. Growth Des. XXXX, XXX, XXX−XXX

Crystal Growth & Design

Article

investigated, but also their formation could not be rationalized in most cases.3,58−63,70−75 Moreover, although stabilization of salts, cocrystals, and salt cocrystals in closely related organic systems is known,49−53 such a report in metal complexes is still lacking. Clearly, further exploration of multicomponent crystals of metal complexes deserves attention, and this structural aspect in heterometallic copper(II)−tin(II/IV) systems derived from some particular ligands, which are known to stabilize cocrystals (vide infra), is the aim of the present investigation. The single76−84 (H2LS, Chart S1, Supporting Information) and double15−29,58−63,84−100 (H2LOMe or H2LOEt, Chart S1, Supporting Information) compartmental Schiff bases obtained on 2:1 condensation of salicylaldehyde/2-hydroxyacetophenone/3-methoxysalicylaldehyde/3-ethoxysalicylaldehyde with a diamine have been widely utilized to derive varieties of heterometallic systems by reacting copper(II)/nickel(II)/zinc(II) mononuclear metallo-ligands with a second metal ion from several parts of the Periodic Table. Notably, in spite of being closely similar ligands, H2LOMe and H2LOEt have already shown a remarkable difference in a number of cases3,98−100 in terms of the nature of the products. It has been understood that one/ two water molecules can interact with the O(phenoxido)2O(ethoxido)2/O(phenoxido)2O(methoxido)2 compartment by forming bifurcated hydrogen bonds, resulting in the stabilization of inclusion products and a variety of two-component and even three-component cocrystals.3,58−63 However, the O(phenoxido)2O(ethoxido)2 compartment is more accessible to water molecule(s) than the O(phenoxido)2O(methoxido)2 compartment, and therefore the tendency to stabilize cocrystals in H2LOEt systems is much greater than that in H2LOMe systems. Regarding tin(II/IV) as a component in heterometallic systems derived from the above-mentioned single/double compartmental ligands, a few nickel(II)/cobalt(III)/zinc(II)/oxovanadium(IV)−tin(II)/tin(IV) compounds,15−29 derived from H2LS/ H2LOMe, are known. Some of them are cocrystals as well.18,19 However, no such heterometallic compound from the H2LOEt system has been reported, although one can anticipate from previous studies that the compounds from this ligand system should be more interesting in terms of multicomponent crystals. Moreover, the use of copper(II) metallo-ligands and a comparative study of the heterometallic copper(II)−tin(II/ IV) systems derived from the two similar ligands (H2LOMe and H2LOEt) may reveal some new types of structures/cocrystals and information, which is in line with the aim of the present investigation. Accordingly, we have reacted to a few dialkyl/ diaryldichloridotin(IV) compounds or SnCl2 salt with the metallo-ligands [CuL1(H2O)] and [CuL2⊂(H2O)], where H2L1 and H2L2 are N,N′-ethylenebis(3-methoxysalicylaldimine) and N,N′-ethylenebis(3-ethoxysalicylaldimine), respectively (Chart 1 and Scheme 1). Herein, we report the syntheses, characterization, and molecular and supramolecular structures of the resulting eight CuIISnIV salt cocrystals/cocrystals [CuL1]2·[SnMe2Cl4]2−·(H2ED)2+ (1), [CuL1]2·[SnEt2Cl4]2−· (H2ED)2+·0.5H2O (2), [CuL1]2·[Sn(n-Bu)2Cl4]2−·(H2ED)2+ (3), [CuL 1 ] 2 ·[SnPh 2 Cl 4 ] 2− ·(H 2 ED) 2 + (4), [CuL 1 ] 2 · [SnPh2Cl4]2−·(H2ED)2+·2MeOH (5), [CuL2]2· [SnMe2Cl2(H2O)2]·0.2H2O (6), [CuL2]·[Sn(n-Bu)2Cl2(H2O)] (7) and [CuL2]2·[SnPh2Cl4]2−·(H2ED)2+ (8) and two CuIISnII salts [CuL1SnCl]+·[SnCl3]− (9) and [CuL2SnCl]+·[SnCl3]− (10) (ED = 1,2-ethylenediamine) (Scheme 1). Comparison of the present systems with the previously published related systems reveals some interesting aspects in structural

Chart 1. Chemical Diagrams of the Metallo-Ligands [CuL1(H2O)] and [CuL2⊂(H2O)]

coordination chemistry and the area of multicomponent crystals.

■

EXPERIMENTAL SECTION

Materials and Physical Methods. All the reagents and solvents were purchased from commercial sources and used as received. The two ligands H2L1 and H2L2 and the two metallo-ligands [CuL1(H2O)] and [CuL2⊂(H2O)] were synthesized following the reported procedures.58,59,98,101−104 NMR spectra of H2L1 and H2L2 were obtained on a Bruker 400 MHz spectrometer using tetramethylsilane [Si(CH3)4] as an internal reference. The infrared spectra (400−4000 cm−1) were recorded on a Bruker-Optics Alpha−T spectrophotometer in KBr pellets; abbreviations: s = strong, m = medium, w = weak, and br = broad. Elemental analyses were performed on a PerkinElmer 2400 II analyzer. Syntheses. [CuL1]2·[SnMe2Cl4]2−·(H2ED)2+ (1). To a stirred methanol suspension (10 mL) of [CuL1(H2O)] (0.102 g, 0.25 mmol) was added a methanol solution (5 mL) of SnMe2Cl2 (0.055 g, 0.25 mmol). After being stirred for 5 min, the resulting dark brown solution was filtered and kept at room temperature. After 1 day, the formed dark brown crystals, suitable for X-ray diffraction analysis, were collected by filtration and washed with cold methanol. Yield: 0.058 g (41%). Anal. Calcd for C40H52Cl4N6O8Cu2Sn (M = 1132.44): C, 42.42; H, 4.63; N, 7.42%. Found: C, 42.47; H, 4.67; N, 7.39%. FT-IR data (KBr, cm−1): ν(CN), 1639 (s); ν(Sn−C), 642 (w). [CuL1]2·[SnEt2Cl4]2−·(H2ED)2+·0.5H2O (2). To a stirred methanol suspension (10 mL) of [CuL1(H2O)] (0.102 g, 0.25 mmol) was added a methanol solution (5 mL) of SnEt2Cl2 (0.062 g, 0.25 mmol). After being stirred for 5 min, the resulting brown solution was filtered and kept at room temperature. After 1 day, the deposited green crystals, suitable for X-ray diffraction analysis, were collected by filtration and washed with cold methanol. Yield: 0.073 g (46%). Anal. Calcd for C42H57Cl4N6O8.5Cu2Sn (M = 1169.55): C, 43.13; H, 4.91; N, 7.19%. Found: C, 43.27; H, 4.87; N, 7.23%. FT-IR data (KBr, cm−1): ν(H2O), 3461 (br); ν(CN), 1640 (s); ν(Sn−C), 645 (w). [CuL1]2·[Sn(n-Bu)2Cl4]2−·(H2ED)2+ (3). To a stirred methanol suspension (10 mL) of [CuL1(H2O)] (0.102 g, 0.25 mmol) was added a methanol solution (5 mL) of Sn(n-Bu)2Cl2 (0.076 g, 0.25 mmol). After being stirred for 5 min, the resulting brown solution was filtered and kept at room temperature. After 1 day, the formed green crystals, suitable for X-ray diffraction analysis, were collected by filtration and washed with cold methanol. Yield: 0.060 g (40%). Anal. Calcd for C46H64Cl4N6O8Cu2Sn (M = 1216.60): C, 45.41; H, 5.30; N, 6.91%. Found: C, 45.50; H, 5.26; N, 6.93%. FT-IR data (KBr, cm−1): ν(CN), 1643 (s); ν(Sn−C), 640 (w). [CuL1]2·[SnPh2Cl4]2−·(H2ED)2+ (4). To a stirred ethanol suspension (10 mL) of [CuL1(H2O)] (0.102 g, 0.25 mmol) was added an ethanol solution (5 mL) of SnPh2Cl2 (0.086 g, 0.25 mmol). After being stirred for 5 min, the resulting dark brown solution was filtered and kept at room temperature. After 1 day, the formed dark brown crystals, suitable for X-ray diffraction analysis, were collected by filtration and B



Article

Scheme 1. Synthesis of Compounds 1−10 from the Metallo-Ligand [CuL1(H2O)] (for 1−5 and 9) or [CuL2⊂(H2O)] (for 6−8 and 10)

being stirred for 5 min, the resulting dark brown solution was filtered and kept at room temperature. After 1 day, the formed brown crystals, suitable for X-ray diffraction analysis, were collected by filtration and washed with cold methanol. Yield: 0.070 g (43%). Anal. Calcd for C54H56Cl4N6O8Cu2Sn (M = 1304.61): C, 49.71; H, 4.33; N, 6.44%. Found: C, 49.82; H, 4.29; N, 6.47%. FT-IR data (KBr, cm−1): ν(C N), 1635 (s); ν(Sn−C), 646 (w). [CuL1SnCl]+·[SnCl3]− (9). To a stirred methanol suspension (30 mL) of [CuL1(H2O)] (0.102 g, 0.25 mmol) was added a methanol solution (10 mL) of SnCl2 (0.095 g, 0.50 mmol). After being stirred for 5 min, the resulting light violet solution was filtered and kept at room temperature. After 1 day, the formed brown crystals, suitable for X-ray diffraction analysis, were collected by filtration and washed with cold methanol. Yield: 0.146 g (76%). Anal. Calcd for C18H18Cl4N2O4CuSn2 (M = 769.06): C, 28.11; H, 2.36; N, 3.64%. Found: C, 28.06; H, 2.39; N, 3.62%. FT-IR data (KBr, cm−1): ν(CN), 1637 (s). [CuL2SnCl]+·[SnCl3]− (10). To a stirred acetone suspension (35 mL) of [CuL2⊂(H2O)] (0.109 g, 0.25 mmol), was added a methanol solution (10 mL) of SnCl2 (0.095 g, 0.50 mmol). Immediately the resulted clear light violet solution was filtered and kept at room temperature. Within 1 h, the formed light orange crystals, suitable for X-ray diffraction analysis, were collected by filtration and washed with acetone. Yield: 0.169 g (85%). Anal. Calcd for C20H22Cl4N2O4CuSn2 (M = 797.11): C, 30.13; H, 2.78; N, 3.51%. Found: C, 30.25; H, 2.81; N, 3.49%. FT-IR data (KBr, cm−1): ν(CN), 1644 (s). Crystal Structure Determination. X-ray quality crystals of all compounds (1−10) were immersed in cryo-oil, mounted in a Nylon loop and measured at 303 K. Intensity data were collected using a Bruker APEX II SMART CCD diffractometer with graphite monochromated Mo−Kα (λ = 0.71073 Å) radiation. Data were collected using omega scans of 0.5° per frame, and full sphere of data were obtained. Cell parameters were retrieved using Bruker SMART software105 and refined using Bruker SAINT105 on all the observed reflections. Data were corrected for absorption effects using the multiscan method (SADABS).105 Structures were solved by direct methods by using the SHELXS-2014 package106 and refined with SHELXL-2014.106 Calculations were performed using the WinGX System-Version 2014.1.107 The hydrogen atoms attached to carbon

washed with cold ethanol. Yield: 0.061 g (39%). Anal. Calcd for C50H56Cl4N6O8Cu2Sn (M = 1256.57): C, 47.79; H, 4.49; N, 6.69%. Found: C, 47.87; H, 4.55; N, 6.65%. FT-IR data (KBr, cm−1): ν(C N), 1636 (s); ν(Sn−C), 644 (w). [CuL1]2·[SnPh2Cl4]2−·(H2ED)2+·2MeOH (5). To a stirred methanol suspension (10 mL) of [CuL1(H2O)] (0.102 g, 0.25 mmol) was added a methanol solution (5 mL) of SnPh2Cl2 (0.086 g, 0.25 mmol). After being stirred for 5 min, the resulting dark brown solution was filtered and kept at room temperature. After 1 day, the formed green crystals, suitable for X-ray diffraction analysis, were collected by filtration and washed with cold methanol. Yield: 0.061 g (37%). Anal. Calcd for C52H64Cl4N6O10Cu2Sn (M = 1320.66): C, 47.29; H, 4.88; N, 6.36%. Found: C, 47.38; H, 4.92; N, 6.31%. FT-IR data (KBr, cm−1): ν(C N), 1636 (s); ν(Sn−C), 645 (w). [CuL2]2·[SnMe2Cl2(H2O)2]·0.2H2O (6). To a stirred methanol suspension (15 mL) of [CuL2⊂(H2O)] (0.109 g, 0.25 mmol) was added a methanol solution (10 mL) of SnMe2Cl2 (0.055 g, 0.25 mmol). After being stirred for 5 min, the resulting dark brown solution was filtered and kept at room temperature. After 3 days, the formed dark brown crystals, suitable for X-ray diffraction analysis, were collected by filtration and washed with cold methanol. Yield: 0.089 g (65%). Anal. Calcd for C42H54.4Cl2N4O10.2Cu2Sn (M = 1095.16): C, 46.06; H, 5.01; N, 5.12%. Found: C, 45.96; H, 5.04; N, 5.07%. FT-IR data (KBr, cm−1): ν(H2O), 3433 (br); ν(CN), 1636 (s); ν(Sn−C), 642 (w); ν(Sn−O), 466 (w). [CuL2]·[Sn(n-Bu)2Cl2(H2O)] (7). To a stirred methanol suspension (15 mL) of [CuL2⊂(H2O)] (0.109 g, 0.25 mmol) was added a methanol solution (10 mL) of Sn(n-Bu)2Cl2 (0.076 g, 0.25 mmol). After being stirred for 5 min, the resulting dark brown solution was filtered and kept at room temperature. Within a week, the formed orange crystals, suitable for X-ray diffraction analysis, were collected by filtration and washed with cold methanol. Yield: 0.133 g (72%). Anal. Calcd for C28H42Cl2N2O5CuSn (M = 739.76): C, 45.46; H, 5.72; N, 3.79%. Found: C, 45.39; H, 5.75; N, 3.81%. FT-IR data (KBr, cm−1): ν(H2O), 3401 (br); ν(CN), 1632 (s); ν(Sn−C), 643 (w); ν(Sn− O), 470 (w). [CuL2]2·[SnPh2Cl4]2−·(H2ED)2+ (8). To a stirred methanol suspension (15 mL) of [CuL2⊂(H2O)] (0.109 g, 0.25 mmol) was added a methanol solution (10 mL) of SnPh2Cl2 (0.086 g, 0.25 mmol). After C



Article

Figure 1. Idealized ball and stick presentations of the crystal structures of 1−5. Color codes are shown in the legend of the figure of 1. All H atoms except those participating in H-bonding are omitted for clarity. of one of the butyl group was found to be disordered, and a better Rvalue was obtained by considering the s.o.f. ratio of the atoms (C26A:C26B) as 0.5:0.5. Corresponding methylene hydrogen atoms were then inserted at geometrically calculated positions and included in the refinement using the riding-model approximation, but they come very close to other H atoms as suitable positions are not available for them. Least square refinements with anisotropic thermal motion parameters for all the non-hydrogen atoms were employed. Crystallographic data are summarized in Table S1 (Supporting Information).

atoms were inserted at geometrically calculated positions and included in the refinement using the riding-model approximation, while those attached to nitrogen (in 1−5 and 8) or oxygen atoms (in 6 and 7) were located in a difference Fourier synthesis and included in the final refinement at positions calculated from the geometry of the molecules using the riding model, with isotropic vibration parameters. Their coordinates were blocked during the refinement process, and the isotropic thermal parameter was set at 1.5 times the average thermal parameter of the parent atoms. Uiso(H) were defined as 1.2Ueq of the parent carbon atoms for phenyl and methylene residues and 1.5Ueq of the parent carbon atom for the methyl group. A disordered solvent molecule in 2 was removed with SQUEEZE108 routine of PLATON109 and was not used in the final refinement. Electron count fits for half of a water molecule per asymmetric unit which is in accord with the microanalytical data. Concerning the compound 7, the terminal carbon atoms of both n-butyl groups seem to be disordered, but attempts to get reasonable model were not successful. Another carbon atom (C26)

■

RESULTS AND DISCUSSION

Synthesis and Characterization. Characterization of the two ligands H2L1 and H2L2 and the two metallo-ligands [CuL1(H2O)] and [CuL2⊂(H2O)] by elemental analyses, single crystal X-ray structures, and IR/1H NMR (300 D



Article

Figure 2. (A) One-dimensional supramolecular structure in [CuL1]2·[SnMe2Cl4]2−·(H2ED)2+ (1), resulted due to N−H···O and N−H···Cl hydrogen bonds and Cu···Cl semicoordination. Color codes: as shown in the legend of the figure of 1. All H atoms except those participating in Hbonding are omitted for clarity. (B) Presentation of the one-dimensional chain as interconnections of vicinal four blade electric fans.

3461, 3433, and 3401 cm−1, respectively. All 10 compounds were also characterized by elemental analyses and single crystal X-ray diffraction. Description of Crystal Structures. Compounds 1−5. Idealized ball and stick presentations of the crystal structures of heterobimetallic compounds [CuL1]2·[SnMe2Cl4]2−·(H2ED)2+ (1), [CuL1]2·[SnEt2Cl4]2−·(H2ED)2+·0.5H2O (2), [CuL1]2· [Sn(n-Bu) 2 Cl 4 ] 2− ·(H 2 ED) 2+ (3), [CuL 1 ] 2 ·[SnPh 2 Cl 4 ] 2− · (H2ED)2+ (4), and [CuL1]2·[SnPh2Cl4]2−·(H2ED)2+·2MeOH (5), derived from the metallo-ligand [CuL1(H2O], are depicted in Figure 1 (the ORTEP diagrams of 1−5 are shown in Figure S1, Supporting Information), while the 1-D polymeric topologies in 1−5 are shown in Figures 2 (for 1) and S2 (for 2−5; Supporting Information). Their important geometric values are included in Table 1. Single crystal X-ray structures reveal that all of 1−5 are isostructural and three-component [1×2+1×1+1×1] salt cocrystals, comprised of two neutral [CuL1] moieties, one dianion [SnR2Cl4]2− (R = Me (1), Et (2), n-Bu (3), Ph (4 and 5)), and one doubly protonated 1,2ethylenediammonium dication [H 3 NCH 2 CH 2 NH 3 ] 2 + (H2ED2+). As shown in Figures 1/2/S2 (Supporting Information), the three components in 1−5 are similarly interlinked through N− H···O and N−H···Cl hydrogen bonds and Cu···Cl semicoordination to generate similar one-dimensional (1-D) topology. Two of the three hydrogen atoms of each NH3+ site of H2ED2+ form bifurcated N−H···O hydrogen bonds with one phenoxido and one methoxido oxygen atoms of one [CuL1] moiety. Thus, each H2ED2+ interacts with two [CuL1], forming a supramolecular dimer. The remaining hydrogen atom of each NH3+ site interacts with one chloride center of the [SnR2Cl4]2− moiety, and such N−H···Cl hydrogen bond takes place between two trans chlorides of a [SnR2Cl4]2− and two NH3+ of two supramolecular dimers. Each of the remaining two trans chlorides of a [SnR2Cl4]2− moiety is semicoordinated with a copper(II) center. As a result, one [SnR2Cl4]2− moiety is surrounded by two supramolecular dimers, i.e., four [CuL1] moieties, by two Cu···Cl semicoordinations, and two N−H···Cl hydrogen bonds. All in all, in all of 1−5, the weak interactions

MHz)/ 13 C NMR/mass spectra was reported previously. 58,59,98,101−104 Before using as the reactants, we characterized these four starting materials by elemental analyses and IR/1H NMR (400 MHz) spectra, which are well matched with the composition and reported data. The 300 and 400 MHz 1 H NMR data of H2L1 and H2L2 are compared in Table S2. Reactions of the metallo-ligand [CuL 1 (H 2 O)] with diorganotin(IV) dichloride SnR2Cl2 in methanol or ethanol produce five similar three-component salt cocrystals with a general formula [CuL1]2·[SnR2Cl4]2−·(H2ED)2+ [excluding the solvent of crystallization; R = Me (1), Et (2), n-Bu (3), and Ph (4 and 5); ED = 1,2-ethylenediamine] at room temperature and under open atmosphere (Scheme 1). Analogous reactions with the other metallo-ligand [CuL2⊂H2O] produce three heterometallic systems, two of which are two-component cocrystals [CuL 2 ] 2 ·[SnMe 2 Cl 2 (H 2 O) 2 ]·0.2H 2 O (6) and [CuL2]·[Sn(n-Bu)2Cl2(H2O)] (7), while the third one is a three-component salt cocrystals [CuL 2 ] 2 ·[SnPh 2 Cl 4 ] 2− · (H2ED)2+ (8), similar to 1−5. Two heterodinuclear CuIISnII salts [CuL1SnCl]+·[SnCl3]− (9) and [CuL2SnCl]+·[SnCl3]− (10) are isolated from the reaction mixtures of SnCl2 with [CuL1(H2O)] and [CuL2⊂H2O], respectively, in methanol (Scheme 1). Initially, a metallo-ligand and the corresponding tin(IV) or tin(II) salt were mixed in a 1:1 ratio for the preparation of all the compounds, but better yields were obtained for 9 and 10 from 1:2 (the ratio of the reactants in the products) mixture of [CuL1(H2O)]/[CuL2⊂H2O] and SnCl2. Compounds 1−5 and 8 were isolated with lower yields, while 6, 7, 9, and 10 were obtained in good or very good yields. Notably, a fraction of the metallo-ligands is hydrolyzed for the in situ generation of ethylenediammonium cation H2ED2+ during the syntheses of 1−5 and 8, which is the reason for their lower yields. In the IR spectra, all of 1−10 exhibit a medium intensity absorption in the 1632−1644 cm−1 range due to ν(CN). A weak band in the 640−646 cm−1 range in the IR spectra of 1−8 can be assigned to the Sn−C bond, while the bands for Sn−O in 6 and 7 are observed at 466 and 470 cm−1, respectively. The water stretching for 2, 6, and 7 is found as a broad band at E


F

∠Cu···Cl−Sn intermolecular Cu···Cu (minimum) displacement of Cu from N2O2 basal plane displacement of Nammonium from l.s. plane of ligand O4 cavity displacement of Owater from l.s. plane of ligand O4 cavity

∠Cl−Sn−Cl (trans) ∠C−Sn−C (trans) ∠H2O−Sn−OH2 ∠H2O−Sn−Cl ∠All cis around Sn

∠Nimine−Cu−Ophenoxo

Sn−Owater Sn−Cl

Cu····Cl Sn−Corgano

Cu−Ophenoxo

Cu−Nimine

∠between the l.s. planes of the aromatic rings

CN

88.86(7)− 91.14(7) 132.47 4.155 0.117 0.109

2.6102(5), 2.6304(5) 176.82(6), 164.89(6) 180.0, 180.0 180.0

1.9548(16), 1.9441(16) 1.9171(13), 1.9233(13) 2.908 2.103(2)

1.276(3), 1.280(3) 19.40

1

129.60, 132.53 3.749 0.108, 0.080 0.138, 0.002

86.31(15)−93.30(15)

2.5825(10), 2.6279(10), 2.6487(10), 2.6885(10) 172.16(14), 173.11(13), 168.05(11), 176.04(11) 179.52(4), 178.41(4) 178.1(2)

1.940(3), 1.945(3), 1.948(3), 1.944(3) 1.924(2), 1.927(2), 1.925(2), 1.929(2) 2.946, 2.996 2.127(5), 2.127(4)

1.275(5), 1.266(5), 1.274(4), 1.277(4) 9.53, 3.63

2 1.281(4), 1.276(4) 8.30

4

87.62(2)− 92.38(2) 131.19 6.719 0.088 0.032

2.5990(6), 2.6746(6) 170.05(8), 176.47(8) 180.0, 180.0 180.0

89.27(2)− 90.73(2) 154.96 5.033 0.035 0.169

2.5593(7), 2.5948(6) 174.19(10), 176.79(10) 180.0, 180.0 180.0

Surrounding the Metal Atoms 1.944(2), 1.937(2) 1.966(2) 1.9199(15), 1.9176(18), 1.9329(15) 1.9190(18) 2.886 3.127 2.137(2) 2.151(3)

In the Ligands 1.277(3), 1.278(3) 7.54

3

89.34(6)− 90.66(6) 143.41 6.582 0.036 0.339

2.5676(10), 2.6184(9) 173.11(8), 176.18(8) 180.0, 180.0 180.0

1.956(2), 1.948(2) 1.9084(17), 1.9411(17) 3.071 2.154(2)

1.286(3), 1.284(3) 6.42

5

Table 1. Comparison of Some Selected Parameters [Distances (Å) and Angles (deg)] in the Crystal Structures of 1−8 7

3.353 0.039

1.364

1.260 1.676

174.43(8) 83.08(19)− 134.6(2)

2.108(5), 2.144(6) 2.377(3) 2.3430(12), 2.4775(13) 176.17(13), 177.25(13)

1.930(3), 1.931(3) 1.900(3), 1.905(3)

1.297(5), 1.275(5) 5.76

89.03(4)− 90.97(4) 104.44 5.624 0.079

169.66(8), 176.74(8) 180.0 180.0 180.0

2.2649(17) 2.6112(6)

1.937(2), 1.954(2) 1.9139(16), 1.9128(16) 3.094 2.109(3)

1.278(3), 1.275(4) 17.34

6

89.65(6)− 90.35(6) 150.81 5.153 0.036 0.678

2.5700(17), 2.6095(17) 173.8(2), 177.9(2) 180.0, 180.0 180.0

1.942(5), 1.933(6) 1.899(4), 1.915(4) 3.247 2.148(6)

1.264(9), 1.275(9) 12.97

8

Crystal Growth & Design Article



Article

Table 2. Geometries [Distances in (Å) and Angles in (deg)] for Some Selected Hydrogen Bonds in 1−8 compounds

D−H···A

H···A

D···A

D−H···A

1

N5−H5A···Cl2 N5−H5B···O1 N5−H5B···O2 N5−H5C···O3 N5−H5C···O4 N5−H5A···Cl4 N5−H5B···O2 N5−H5B···O4 N5−H5C···O3 N5−H5C···O1 N6−H6A···Cl2 N6−H6B···O5 N6−H6B···O7 N6−H6C···O8 N6−H6C···O6 N3−H3A···Cl2 N3−H3B···O3 N3−H3B···O4 N3−H3C···O1 N3−H3C···O2 N3−H3A···Cl2 N3−H3B···O2 N3−H3B···O4 N3−H3C···O1 N3−H3C···O2 N3−H3A···O1 N3−H3A···O3 N3−H3C···O2 N3−H3C···O4 N3−H3B···Cl1 N3−H3B···Cl2 O5−H5M···Cl2 O5−H5A···O1 O5−H5A···O2 O5−H5B···O3 O5−H5B···O4 O6−H5B···O1 O5−H5B···O1 O5−H5B···O2 O5−H5A···O3 O5−H5A···O4 N3−H3A···O1 N3−H3A···O2 N3−H3B···O3 N3−H3B···O4 N3−H3B···Cl1

2.29 2.08 2.13 2.03 2.14 2.30 1.99 2.18 2.12 2.15 2.38 2.03 2.19 2.10 2.10 2.41 2.14 2.05 1.97 2.24 2.53 2.21 2.05 1.94 2.23 2.19 2.10 2.01 2.18 2.69 2.68 2.40 2.32 1.85 1.92 2.24 2.25 2.28 2.12 2.17 2.36 2.295 2.054 2.044 2.243 2.609

3.173 2.808 2.896 2.805 2.856 3.178 2.797 2.846 2.917 2.841 3.226 2.820 2.901 2.849 2.801 3.227 2.786 2.832 2.801 2.888 3.345 2.785 2.859 2.776 2.833 2.762 2.826 2.778 2.914 3.404 3.327 3.224 3.123 2.684 2.722 3.049 3.040 2.854 2.940 2.741 3.136 2.765 2.864 2.760 2.913 3.332

170.0 138.4 143.9 145.3 137.4 166.7 150.6 131.3 149.4 133.7 159.8 147.2 136.7 141.8 135.6 152.1 129.0 145.8 155.4 129.2 152.2 122.0 150.1 156.3 124.3 121.6 138.0 143.1 138.8 138.1 130.8 161.1 140.8 142.9 139.8 141.6 162.8 124.8 160.0 123.5 150.0 116.15 163.79 145.03 138.59 146.71

2

3

4

5

6

7

8

involving the protonated amine sites, O(phenoxido)2O(methoxido)2 compartment, CuII center, and dialkyl/phenyl tetrachloridostannate(IV) moiety result in the generation of a similar 1-D topology which looks like a four blade electric fan (Figure 2). However, the overall supramolecular topology in 1 and 2 is more extended due to π···π stacking interactions which take place between the 1-D chains to build up two-dimensional (2-D) supramolecular structures (Figures S3 and S4, Supporting Information). It is worth mentioning that the five H-bonding interactions (four N−H···O and one N−H···Cl) in 1−5 are reasonably strong as evidenced by their geometrical parameters (Table 2).

symmetry −x, 1 − y, −z; −x, 1 − y, 1 − z

−x, 1 − y, 2 − z

1 − x, 1 − y, 1 − z

−0.5 + x, 1.5 − y, −0.5 + z; 0.5 + x, 1.5 − y, 0.5 + z

2 − x, 1 − y, 1 − z

The coordination environments of the copper(II) and tin(IV) centers in 1−5 are distorted square planar and distorted octahedral, respectively. The bond lengths and bond angles involving the copper(II) centers in 1−5 are as usual (Table 1).58−60,98 In [SnR2Cl4]2− of 1−5, the cis and trans bond angles involving tin(IV) are very much comparable to a perfect octahedral considering the experimental error (Table 1). However, two Sn−C bonds are in trans positions and, as expected, significantly shorter than four equatorial Sn−Cl bonds, indicating that the geometry around the tin(IV) center is compressed octahedral. G



Article

Figure 3. Idealized ball and stick presentations of the crystal structures of 6−8. Color codes: as shown in the legend of the figure of 1. All H atoms except those participating in H-bonding are omitted for clarity.

interlinked by a hexacoordinated organotin(IV) molecule as the tecton. It is also a [1×2+1×1] trinuclear cocrystal of two CuII and one SnIV units. On the other hand, the only coordinated water molecule in 7 similarly interacts with one O4 compartment, forming a [1×1+1×1] dinuclear cocrystal of one SnIV and one CuII units. In addition to the water···O4 interactions, there is also Cu···Cl semicoordination between [CuL2] and [Sn(n-Bu)2Cl2(H2O)] units in 6. However, as observed previously,58−63 the reason for cocrystallization in 6 and 7 is the potential tendency of the O(phenoxido)2O(ethoxido)2 compartment to interact with a water molecule. It is worth mentioning that [1×2+1×1] vs [1×1+1×1] cocrystallization (in 6 and 7) takes place as the function of number of coordinated water molecules in the tecton, which has also been observed previously in the products obtained from the reactions of mononuclear copper(II) compounds and other second metal ions.58−63 Geometrical parameters (Table 2) indicate the H-bonding interactions in 6 and 7 are strong. In addition to the O−H···O interactions, there are also Cu··· O(phenoxido) semicoordinations (3.137 Å) and π···π inter-

As listed in Table 1, Cu···Cl contacts in 4 and 5 are slightly but definitely longer than those in 1−3, which is clearly due to the presence of bulky phenyl group in the formers. Compounds 6−8. Idealized ball and stick presentations of the compounds [CuL2]2·[SnMe2Cl2(H2O)2]·0.2H2O (6), [CuL2]·[Sn(n-Bu)2Cl2(H2O)] (7), and [CuL2]2·[SnPh2Cl4]2−· (H2ED)2+ (8) derived from the metallo-ligand [CuL2⊂H2O] are presented in Figure 3 (the ORTEP diagrams of 6−8 are shown in Figure S5, Supporting Information), while their selected geometric parameters are listed in Table 1. The structures of 6 and 7 reveal that these are two-component cocrystals. The compound 6 contains two monomeric [CuL2] units and a hexacoordinated organotin(IV) molecule [SnMe2Cl2(H2O)2], whereas the compound 7 is comprised of one mononuclear [CuL2] and one pentacoordinated organotin(IV) [Sn(n-Bu) 2Cl2(H2O)] moieties. Each of the two coordinated water molecules in 6 interacts with the O(phenoxido)2O(ethoxido)2 compartment of a [CuL2] unit through bifurcated hydrogen bonds. Thus, the compound 6 is a supramolecular dimer in which two [CuL2] units are H



Article

in 1−5. The values of geometric parameters related to these Hbonds (Table 2) suggest they are strong. The coordination geometry of the copper(II) center in 6−8 is distorted square planar in which the bond distances and angles lie in the usual range.58−60,98 As presented in Table 1, the Cu···Cl contact in 8 is longer than that in 6 and, in fact, the longest among all CuIISnIV compounds (1−8), which is possibly due to the combined steric crowding of the larger ethoxy and bulky phenyl groups. The coordination environment around the [SnPh2Cl4]2− dianion in 8 is similar to that in [SnPh2Cl4]2− dianion in 4 and 5. The coordination geometry of tin(IV) in [SnMe2Cl2(H2O)2] unit of 6 is also distorted octahedral in which the similar ligands occupy the corresponding trans positions. On the other hand, the coordination geometry of the tin(IV) center in the [Sn(n-Bu)2Cl2(H2O)] unit in 7 is distorted trigonal pyramidal (τ = 0.664)110 where the water molecule and one of the two chlorides occupy the axial positions. In 6−8, the Sn−C and Sn−Cl bond distances are in the same ranges as observed for 1−5. The order (C < O < Cl) of atomic radii explains why the Sn−O(water) bonds are shorter and longer than Sn−Cl and Sn−C ones, respectively (Table 1). Compounds 9 and 10. Idealized ball and stick presentations of the compounds [CuL 1 SnCl] + ·[SnCl 3 ] − (9) and [CuL2SnCl]+·[SnCl3]− (10) are shown in Figure 5 (the ORTEP diagrams of 9 and 10 are shown in Figure S7, Supporting Information), while their selected bond contacts and angles are included in Table 3. Their single crystal X-ray structure analyses reveal that they are heterobimetallic, trinuclear CuIISnII2 salts, comprised of two metal components [CuSnL1Cl]+/[CuSnL2Cl]+ and [SnCl3]−. Unlike all CuIISnIV compounds (1−8) where the SnIV center does not occupy the O4 site, one of the SnII ions in 9 and 10 occupies the O4 cavity of the ligand, forming the bis(μ1,1-phenoxido) bridged CuIISnII unit which connects the SnCl3 residue via the Cu···Cl semicoordination.

actions (3.890 Å) in 7 to generate a supramolecular tetramer (Figure 4).

Figure 4. Cu···O(phenoxido), H−O···H and π···π supported supramolecular tetramer in 7. Color codes: as shown in the legend of the figure of 1. All H atoms except those participating in H-bonding are omitted for clarity.

In contrast to the crystal structures of 6 and 7, obtained by reacting [CuL2⊂(H2O)] with SnMe2Cl2 or Sn(n-Bu)2Cl2, the structure of the compound isolated from the reaction of [CuL2⊂H2O] and SnPh2Cl2 reveals that it is a threecomponent [1×2+1×1+1×1] salt cocrystal of composition [CuL2]2·[SnPh2Cl4]2−·(H2ED)2+ (8), similar to those of 1−5. The crystal structure of 8 is comprised of two neutral [CuL2] units, one [SnPh2Cl4]2− anion, and one H2ED2+ cation. It has also five H-bonding interactions (four N−H···O and one N− H···Cl) involving the ethoxido/phenoxido oxygen atoms, the chloride atoms of organotin(IV) moiety, and the ammonium groups of H2ED2+, to stabilize the 1-D supramolecular selfassembly (Figure S6, Supporting Information), similar to those

Figure 5. Crystal structures of 9 and 10. Color codes: as shown in the legend of the figure of 1. All H atoms are omitted for clarity. I



Article

which is also possibly related to the larger ethoxy substituent in 10 in comparison to the methoxy group in 9. Two SnII ions in both 9 and 10 have different coordination environments. The SnII center in the CuIISnII dinuclear unit is pentacoordinated involving O4 cavity of the ligand and one chloride, while that in the [SnIICl3]− anion is trigonal with three chloride atoms (Figure 5). The coordination environment of the SnII center in the CuIISnII dinuclear unit cannot be defined in terms of any regular/distorted geometry. Because of three different noncovalent interactions (Cu···Cl, Sn···Cl, and Sn···Cu), operating between dimeric CuIISnII and [SnIICl3]− moieties of vicinal molecules in 9, an interesting zigzag 1-D supramolecular chain (Figure 6) is formed. The compound 10 has only Cu···Cl and Sn···Cl interactions, which provide support also to form a 1-D associate (Figure 6), but that is much more symmetric and linear in comparison to that in 9. Both 1-D chains consist of alternating [SnIICl3]− residues and dimeric CuIISnII units (Figure 6). Comparison of 1−10 with Previously Published Related Systems. Few CuII/NiII/CoII/VIVO−SnII/SnIV compounds, derived from a few H2LOMe ligands including H2L1, were reported previously.15−29 Most of these are SnIV systems, while two are SnII (NiIISnII) systems.20,21 The oxovandium(IV)−tin(IV) analogues were synthesized from the reactions of the corresponding mononuclear VIVO metallo-ligands with SnIVPh2Cl2/SnIVPh3Cl, and the products are oxo-bridged V O−Sn compounds, where neither phenoxido nor methoxido oxygen atoms are coordinated to SnIV (Type A).24−27 Two CoIISnIV, one ZnIISnIV, and a few NiIISnIV compounds were synthesized by reacting the corresponding metallo-ligands with SnIVR2(NCS)2/SnIVR2(NO3)2 (R = Me, n-Bu, Ph, PhCH2), and those products are diphenoxido-bridged dinuclear MIISnIV systems where the SnIV center occupies the O(phenoxido)2O(methoxido)2 compartment (Type B).15−17,20−23 A few

Table 3. Comparison of Some Selected Parameters [Distances (Å) and Angles (deg)] in the Crystal Structures of 9 and 10 9 In the Ligands CN 1.269(4), 1.272(4) ∠between the l.s. planes of 3.57 the aromatic rings Surrounding the Metal Atoms Cu−Nimine 1.914(3), 1.916(3)

10 1.25(2), 1.27(2) 5.36

Cu−Ophenoxo

1.9065(19), 1.908(2)

Cu···Cl Sn−O

2.856 2.2462(18), 2.2776(19), 2.620, 2.695 2.4561(9), 2.4387(10), 2.4655(11), 2.5652(8) 3.459 172.94(10), 175.46(10) 132.97 3.291

1.890(14), 1.911(13) 1.896(9), 1.915(10) 2.916 2.215(9), 2.225(10), 2.674, 2.725 2.455(5), 2.424(6), 2.445(6), 2.530(5) 3.471 170.7(6), 177.4(6) 127.82 3.236

3.451 0.042 0.091

0.112 0.096

0.260

0.201

Sn−Cl intermolecular Sn····Cl ∠Nimine−Cu−Ophenoxo ∠Cu···Cl−Sn Cu····Sn in bimetallic CuSn unit intermolecular Cu····Sn τ5 parameter for Cu displacement of Cu from the N2O2 basal plane displacement of Sn from the l.s. plane of ligand O4 cavity

The coordination geometry (excluding semicoordination) of the copper(II) center in the bimetallic CuIISnII units of 9 and 10 is, as usual, distorted square planar.58−60 The Cu···Cl contact (2.856 Å) in 9 is shorter than that (2.916 Å) in 10,

Figure 6. Supramolecular 1-D associate in 9 and 10 supported by noncovalent interactions (Cu···Cl, Sn···Cl and Cu···Sn in 9; Cu···Cl and Sn···Cl in 10). Color codes: as shown in the legend of the figure of 1. All H atoms are omitted for clarity. J



Article

NiIISnIV compounds, isolated from similar ligands including H2L1, were prepared by mixing the corresponding metalloligands with SnIVMe2Cl2/SnIVPh2Cl2/SnIVPh3Cl, and they are cocrystals of [NiLOMe] and [SnIVR2Cl2(H2O)]/[SnIVR3Cl(H2O)] (Type C);18,19 the coordinated water molecule interacts with the O(phenoxido)2O(methoxido)2 compartment by forming hydrogen bonds. The reported two NiIISnII compounds, derivatives of H2LOMe ligands, were synthesized by reacting the corresponding mononuclear metallo-ligands with SnCl2/SnBr2, and the products are of similar types, diphenoxido-bridged dinuclear NiIISnII compounds of composition [NiII(Cl/Br)(solvent)L1SnII(Cl/Br)] (Type D).20,21 In contrast to the above-mentioned types, a completely different type of SnII−d-block compound (six only) having SnII in N2O2 compartment of H2LS is known.28,29 Clearly, the Cu I I ···Sn I V cocrystal [CuL 2 ]·[Sn(nBu)2Cl2(H2O)] (7), derived from a H2LOEt ligand, is similar to the Type C NiII···SnIV cocrystals, derived from H2LOMe ligands. Although the CuIISnII systems [CuL1SnCl]+·[SnCl3]− (9) and [CuL2SnCl]+·[SnCl3]− (10) are diphenoxido-bridged dinuclear, as are the Type D NiIISnII compounds, the former are salts due to the presence [SnCl3]− anion and accompanied by Cu···Cl/Sn···Cl/Cu···Sn weak interactions. This way, 9 and 10 may be considered as new types of systems derived from the double-compartment Schiff base ligands. It is evident that the three-component [1×2+1×1+1×1] salt cocrystals 1−5 and 8 of general composition [CuL]2·[SnR2Cl4]2−·(H2ED)2+ (excluding the solvent of crystallization) as well as the two-component [1×2+1×1] cocrystal 6 of composition [CuL 2 ] 2 · [SnMe2Cl2(H2O)2] (6; excluding the solvent of crystallization) are new types of systems. Comparison of the composition of the above-mentioned NiIISnIV Type C cocrystals and salt cocrystals 1−5 reveals the role of the metal ion (CuII or NiII) to govern the stabilization of entirely different types of systems. As already mentioned, many 3d-second metal ion systems including cocrystals, derived from H2LOMe and H2LOEt, have been previously reported.3,58−63,89−100 Interaction of one coordinated molecule (as in 7 and Type C systems) with one O4 compartment or two coordinated water molecules (as in 6) with two O4 compartments have also been observed in other heterometallic systems (not containing tin), derived from H2LOMe/H2LOEt. However, the type of composition and selfassembly aspect in 1−5 and 8 are unique, keeping in mind the various types of compounds derived from these two types of ligands. The variable in the syntheses of 1−5 is basically the R group in SnR2Cl2 (Me in 1, Et in 2, n-Bu in 3, Ph in 4 and 5). However, the stabilization of similar types compounds 1−5 indicates the selectivity of composition and structure, while the starting metallo-ligand is a mononuclear copper(II) system of H2L1. On the other hand, three types of compounds (6, 7 and 8) are isolated from the reactions of different SnR2Cl2 salts (R = Me, n-Bu, Ph) and the starting copper(II) metallo-ligand of H2L2. Thus, H2L2 derived systems, even in this particular case, are showing structural diversity in contrast to the selectivity in the corresponding derivatives of H2L1. Not only is this an interesting observation, but also it again reveals the remarkable difference of the two closely related ligands.3,98−100 In the case of two SnII compounds 9 and 10, however, there is no difference of the two ligands regarding the composition of the final products, which are salts. For the comparison of the coexistence of diammonium and SnCl4R2 (R = alkyl or aromatic groups) moieties in 1−5 and 8

with the possible previously reported related systems containing at least NH3 and a Sn fragment, we made a search for two fragments, X−NH3 (X = any) and SnX6 (X = any) together on the Cambridge Structural Database (CSD ConQuest Version 1.17),76 and it resulted 53 compounds. However, all of them are simple homometallic salts containing organic ammonium and organotin(IV) units. As 1−5 and 8 are heterometallic species containing both a tin unit and an organic ammonium moiety, this aspect may also be considered as an additional significance of these compounds. It has been already mentioned that H2LOMe and H2LOEt show a remarkable difference in terms of the composition of mononuclear and homo-/heteronuclear systems.3,98−100 The differences in the CuIISnIV systems derived from H2L1 (a H2LOMe ligand) and H2L2 (a H2LOEt ligand) have also been already discussed. The drastic differences in some of the previously reported compounds derived from H2L1 and H2L2 have been listed and discussed in Supporting Information.

■

CONCLUSIONS Copper(II) metallo-ligands [CuL1(H2O)] and [CuL2⊂(H2O)] [H2L1 = N,N′-ethylenebis(3-methoxysalicylaldimine) and H2L2 = N,N′-ethylenebis(3-ethoxysalicylaldimine)] have been treated with SnR2Cl2 (R = Me/Et/n-Bu/Ph) and SnCl2, resulting in the formation of eight CuIISnIV and two CuIISnII heterobimetallic compounds. Of the eight CuIISnIV systems, six are three-component [1×2+1×1+1×1] salt cocrystals of general formula [CuLx]2· [SnR2Cl4]2−·(H2ED)2+ (1−5: Lx = L1; 8: Lx = L2; 1: R = Me; 2: R = Et; 3: R = n-Bu; 4, 5, and 8: R = Ph; ED = 1,2ethylenediamine; excluding the solvent of crystallization), one is a [1×2+1×1] trinuclear cocrystal of composition [CuL2]2· [SnMe2Cl2(H2O)2]·0.2H2O (6), and the remaining is a [1×1+1×1] dinuclear cocrystal of composition [CuL2]·[Sn(nBu)2Cl2(H2O)] (7). Two CuIISnII systems [CuL1SnCl]+· [SnCl3]− (9) and [CuL2SnCl]+·[SnCl3]− (10) are salts, containing diphenoxido-bridged dinuclear CuIISnII moiety. The formations of salts/cocrystals/salt cocrystals are well explained in terms of weak interactions. Most of the systems here are weak interactions directed self-assemblies; overall topology: finite in 7 and infinite 1-D in 3−5 and 8−10, and infinite 2-D in 1 and 2. It is worth mentioning that [CuL1]2· [SnPh2Cl4]2−·(H2ED)2+·2MeOH (5) is a solvatomorphic111 form [CuL1]2·[SnPh2Cl4]2−·(H2ED)2+ (4). Salicylaldehyde-diamine (H2LS), 2-hydroxyacetophenonediamine (H2LS), 3-methoxysalicylaldehyde-diamine (H2LOMe), and 3-ethoxysalicylaldehyde-diamine (H2LOEt) may be considered as the members of a broad class of Schiff base ligands that stabilize hundreds of heterometallic CuII/NiII/ZnII/VIVO− second metal ion systems. In this broad family, the 10 compounds 1−10 reported herein, derived from two doublecompartmental H2L1 and H2L2 ligands, are the first examples of CuIISnIV/SnII systems and among only a few examples of heterometallic systems containing SnII/SnIV as the second metal ion. H2L2, which is known to exhibit interesting structural diversity, is utilized for the first time to derive heterometallic systems containing SnII/SnIV as the second metal ion. Comparison of 1−5 with some NiIISnIV systems reveals the interesting role of 3d metal ion in the N2O2 compartment to govern the type of systems. Although dinuclear cores in 9 and 10 are similar to those in two previously reported NiIISnII systems, the presence of [SnCl3]− and accompanied formation of salts is a new observation in such type of systems. On the K



Article

Calcutta. P.C. acknowledges University Grants Commission, Government of India, for a fellowship.

other hand, the cocrystal 6 and, more particularly, salt cocrystals 1−5 and 8 are unique systems in terms of composition and self-assembly. To our knowledge, 1−5 and 8 are the first examples of a heterometallic system containing not only a diammonium:tetrachloridostannate adduct but also any X−NH3:SnX6 one (X = any). The observed selectivity and diversity (formation of 1−5 vs 6−8) as the function of slight change of ligand environment are interesting, strengthening the remarkable difference between the two closely similar ligands. However, it has also been observed that such a difference is effective for SnIV systems but not for SnII ones (9 and 10 are similar). A few reports of three types of organic multicomponent crystals (salts, cocrystals, and salt cocrystals) with a common organic component are known.49−53 On the other hand, stabilization of three types of metallo-organic multicomponent crystals (salts, cocrystals, and salt cocrystals) containing metal ions (CuII and SnII/SnIV) of the same elements (Cu and Sn) and derived from similar ligands (H2L1 and H2L2) and even the same ligand (H2L2; 10 is a salt, 6 and 7 are cocrystals and 8 is a salt cocrystal) is unprecedented, to the best of our knowledge. Selectivity, diversity, difference of closely similar ligands, new types of systems, role of 3d metal ion and oxidation state of tin in governing composition, and stabilization of three types of metallo-organic multicomponent crystals, as observed herein, appear to us as interesting and should be explored further to unveil some other new aspects.

■

■

(1) Melník, M. Heterometallic Coordination Copper (II) Compounds: Classification and Analysis of Crystallographic and Structural Data; Nova Science Publishers: New York, 1999. (2) Zhang, W.-H.; Liu, Q.; Lang, J.-P. Coord. Chem. Rev. 2015, 293− 294, 187−210. (3) Jana, A.; Mohanta, S. CrystEngComm 2014, 16, 5494−5515. (4) Buchwalter, P.; Rosé, J.; Braunstein, P. Chem. Rev. 2015, 115, 28−126. (5) Hernandez-Molina, R. H.; Sokolov, M. N.; Sykes, A. G. Acc. Chem. Res. 2001, 34, 223−230. (6) Timco, G. A.; McInnes, E. J. L.; Winpenny, R. E. P. Chem. Soc. Rev. 2013, 42, 1796−1806. (7) Andruh, M. Chem. Commun. 2007, 2565−2577. (8) John, Ł.; Sobota, P. Acc. Chem. Res. 2014, 47, 470−481. (9) Marinescu, G.; Andruh, M.; Lloret, F.; Julve, M. Coord. Chem. Rev. 2011, 255, 161−185. (10) Li, H.; Yao, Z.-J.; Liu, D.; Jin, G.-X. Coord. Chem. Rev. 2015, 293−294, 139−157. (11) Nesterov, D. S.; Kokozay, V. N.; Dyakonenko, V. V.; Shishkin, O. V.; Jezierska, J.; Ozarowski, A.; Kirillov, A. M.; Kopylovich, M. N.; Pombeiro, A. J. L. Chem. Commun. 2006, 4605−4607. (12) Andruh, M.; Branzea, D. G.; Gheorghe, R.; Madalan, A. M. CrystEngComm 2009, 11, 2571−2584. (13) Andruh, M. Dalton Trans. 2015, 44, 16633−16653. (14) Hazra, S.; Bhattacharya, S.; Singh, M. K.; Carrella, L.; Rentschler, E.; Weyhermueller, T.; Rajaraman, G.; Mohanta, S. Inorg. Chem. 2013, 52, 12881−12892. (15) Calligaris, M.; Randaccio, L.; Barbieri, R.; Pellerito, L. J. Organomet. Chem. 1974, 76, C56−C58. (16) Clarke, B.; Clarke, N.; Cunningham, D.; Higgins, T.; McArdle, P.; Nı ́ Cholchuin, M. N.; O’Gara, M. J. Organomet. Chem. 1998, 559, 55−64. (17) Clarke, B.; Cunningham, D.; Gallagher, J. F.; Higgins, T.; McArdle, P.; McGinley, J.; Cholchuin, M. N.; Sheerin, D. J. Chem. Soc., Dalton Trans. 1994, 2473−2482. (18) Clarke, N.; Cunningham, D.; Higgins, T.; McArdle, P.; McGinley, J.; O’Gara, M. J. Organomet. Chem. 1994, 469, 33−40. (19) Cunningham, D.; Gallagher, J. F.; Higgins, T.; McArdle, P.; McGinley, J.; O’Gara, M. J. Chem. Soc., Dalton Trans. 1993, 2183− 2190. (20) Oz, S.; Arici, C.; Emregul, K. C.; Ergun, U.; Atakol, O.; Kenar, A. Z. Kristallogr. 2007, 222, 249−254. (21) Cunningham, D.; Gallagher, J. F.; Higgins, T.; McArdle, P.; Sheerin, D. J. Chem. Soc., Chem. Commun. 1991, 432−433. (22) Boyce, M.; Clarke, B.; Cunningham, D.; Gallagher, J. F.; Higgins, T.; McArdle, P.; Nı ́ Cholchuin, M. N.; O’Gara, M. J. Organomet. Chem. 1995, 498, 241−250. (23) Cunningham, D.; Higgins, T.; Kneafsey, B.; McArdle, P.; Simmie, J. J. Chem. Soc., Chem. Commun. 1985, 231−232. (24) Cashin, B.; Cunningham, D.; Daly, P.; McArdle, P.; Munroe, M.; Nı ́ Chonchubhair, N. Inorg. Chem. 2002, 41, 773−782. (25) Choudhary, N. F.; Hitchcock, P. B.; Leigh, G. J.; Ng, S. W. Inorg. Chim. Acta 1999, 293, 147−154. (26) Cashin, B.; Cunningham, D.; Gallagher, J. F.; McArdle, P.; Higgins, T. J. Chem. Soc., Chem. Commun. 1989, 1445−1446. (27) Cashin, B.; Cunningham, D.; Gallagher, J. F.; McArdle, P.; Higgins, T. Polyhedron 1989, 8, 1753−1755. (28) Agustin, D.; Rima, G.; Gornitzka, H.; Barrau, J. Inorg. Chem. 2000, 39, 5492−5495. (29) Agustin, D.; Rima, G.; Gornitzka, H.; Barrau, J. Eur. J. Inorg. Chem. 2000, 2000, 693−702. (30) Hilbert, J.; Näther, C.; Bensch, W. Inorg. Chem. 2014, 53, 5619− 5630. (31) Sindlinger, C. P.; Weiss, S.; Schubert, H.; Wesemann, L. Angew. Chem., Int. Ed. 2015, 54, 4087−4091.

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.cgd.6b00321. Chart S1. Tables S1, S2, and S3 for the crystallographic data of 1−10, 1H NMR data of H2L1/H2L2 and the list of metal complexes derived from H2L1/H2L2, respectively. Figures S1−S7 (PDF) Accession Codes

CCDC 1420639−1420645 and 1428293−1428295 for 1−10 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by emailing data_request@ccdc. cam.ac.uk, or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033.

■

REFERENCES

AUTHOR INFORMATION

Corresponding Authors

*(S.H.) E-mail: [email protected]. *(S.M.) E-mail: [email protected]. Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS Financial support from the Fundaçaõ para a Ciência e a Tecnologia (FCT), Portugal, for fellowship (SFRH/BPD/ 78264/2011) to S.H. and for the UID/QUI/00100/2013 project is gratefully acknowledged. S.M. acknowledges Department of Science and Technology, Government of India (FIST and SR/S1/IC-42/2011). Crystallography was performed at the DST-FIST, India-funded Single Crystal X-ray Diffractometer Facility at the Department of Chemistry, University of L



Article

(65) Mannava, M. K. C.; Suresh, K.; Nangia, A. Cryst. Growth Des. 2016, 16, 1591−1598. (66) Rajput, L.; Sanphui, P.; Desiraju, G. R. Cryst. Growth Des. 2013, 13, 3681−3690. (67) Banerjee, R.; Bhatt, P. M.; Ravindra, N. V.; Desiraju, G. R. Cryst. Growth Des. 2005, 5, 2299−2309. (68) Nayak, M.; Sarkar, S.; Lemoine, P.; Sasmal, S.; Koner, R.; Sparkes, H. A.; Howard, J. A. K.; Mohanta, S. Eur. J. Inorg. Chem. 2010, 2010, 744−752. (69) Jana, A.; Weyhermüller, T.; Mohanta, S. CrystEngComm 2013, 15, 4099−4106. (70) Chou, C.-C.; Su, C.-C.; Tsai, H.-L.; Lii, K.-H. Inorg. Chem. 2005, 44, 628−632. (71) Palaniandavar, M.; Butcher, R. J.; Addison, A. W. Inorg. Chem. 1996, 35, 467−471. (72) Holz, R. C.; Thompson, L. C. Inorg. Chem. 1993, 32, 5251− 5256. (73) Evans, W. J.; Boyle, T. J.; Ziller, J. W. Inorg. Chem. 1992, 31, 1120−1122. (74) Bencini, A.; Benelli, C.; Caneschi, A.; Carlin, R. L.; Dei, A.; Gatteschi, D. J. Am. Chem. Soc. 1985, 107, 8128−8136. (75) Jones, P.; Vagg, R. S.; Williams, P. A. Inorg. Chem. 1984, 23, 4110−4111. (76) Allen, F. H. Acta Crystallogr., Sect. B: Struct. Sci. 2002, 58, 380− 388. (77) Mondal, S.; Mandal, S.; Carrella, L.; Jana, A.; Fleck, M.; Köhn, A.; Rentschler, E.; Mohanta, S. Inorg. Chem. 2015, 54, 117−131. (78) Gonzalez-Riopedre, G.; Bermejo, M. R.; Fernandez-Garcia, M. I.; Gonzalez-Noya, A. M.; Pedrido, R.; Rodriguez-Douton, M. J.; Maneiro, M. Inorg. Chem. 2015, 54, 2512−2521. (79) Zhang, D.; Bian, Y.; Qin, J.; Wang, P.; Chen, X. Dalton Trans. 2014, 43, 945−949. (80) Nguyen, A. I.; Hadt, R. G.; Solomon, E. I.; Tilley, T. D. Chem. Sci. 2014, 5, 2874−2878. (81) Lee, J. W.; Lim, K. S.; Ryu, D. W.; Koh, E. K.; Yoon, S. W.; Suh, B. J.; Hong, C. S. Inorg. Chem. 2013, 52, 8677−8684. (82) Ababei, R.; Pichon, C.; Roubeau, O.; Li, Y.-G.; Brefuel, N.; Buisson, L.; Guionneau, P.; Mathoniere, C.; Clerac, R. J. Am. Chem. Soc. 2013, 135, 14840−14853. (83) Ishikawa, R.; Miyamoto, R.; Nojiri, H.; Breedlove, B. K.; Yamashita, M. Inorg. Chem. 2013, 52, 8300−8302. (84) Miyasaka, H.; Matsumoto, N.; Okawa, H.; Re, N.; Gallo, E.; Floriani, C. J. Am. Chem. Soc. 1996, 118, 981−994. (85) Rouquette, J.; Thibaud, J.-M.; Ferreira, R. A. S.; Carlos, L. D.; Donnadieu, B.; Vieru, V.; Chibotaru, L. F.; Konczewicz, L.; Haines, J.; Guari, Y.; Larionova, J.; Long, J. Angew. Chem., Int. Ed. 2015, 54, 2236−2240. (86) Cametti, M.; Nissinen, M.; Dalla Cort, A.; Rissanen, K.; Mandolini, L. Inorg. Chem. 2006, 45, 6099−6101. (87) Bridonneau, N.; Gontard, G.; Marvaud, V. Dalton Trans. 2015, 44, 5170−5178. (88) Bridonneau, N.; Chamoreau, L.-M.; Lainé, P. P.; Wernsdorfer, W.; Marvaud, V. Chem. Commun. 2013, 49, 9476−9478. (89) Jana, A.; Majumder, S.; Carrella, L.; Nayak, M.; Weyhermueller, T.; Dutta, S.; Schollmeyer, D.; Rentschler, E.; Koner, R.; Mohanta, S. Inorg. Chem. 2010, 49, 9012−9025. (90) Koner, R.; Lin, H.-H.; Wei, H.-H.; Mohanta, S. Inorg. Chem. 2005, 44, 3524−3536. (91) Bhattacharya, S.; Jana, A.; Mohanta, S. CrystEngComm 2013, 15, 10374−10382. (92) Sarkar, S.; Mohanta, S. RSC Adv. 2011, 1, 640−650. (93) Sarkar, S.; Nayak, M.; Fleck, M.; Dutta, S.; Florke, U.; Koner, R.; Mohanta, S. Eur. J. Inorg. Chem. 2010, 2010, 735−743. (94) Bhattacharya, S.; Mondal, S.; Sasmal, S.; Sparkes, H. A.; Howard, J. A. K.; Nayak, M.; Mohanta, S. CrystEngComm 2011, 13, 1029−1036. (95) Nayak, M.; Sarkar, S.; Hazra, S.; Sparkes, H. A.; Howard, J. A. K.; Mohanta, S. CrystEngComm 2011, 13, 124−132.

(32) Kuwabara, T.; Guo, J.-D.; Nagase, S.; Sasamori, T.; Tokitoh, N.; Saito, M. J. Am. Chem. Soc. 2014, 136, 13059−13064. (33) Wachtler, E.; Gericke, R.; Zhechkov, L.; Heine, T.; Langer, T.; Gerke, B.; Pottgen, R.; Wagler, J. Chem. Commun. 2014, 50, 5382− 5384. (34) Almarsson, Ö .; Zaworotko, M. J. Chem. Commun. 2004, 1889− 1896. (35) Steed, J. W. Trends Pharmacol. Sci. 2013, 34, 185−193. (36) Sanphui, P.; Mishra, M. K.; Ramamurty, U.; Desiraju, G. R. Mol. Pharmaceutics 2015, 12, 889−897. (37) Clarke, H. D.; Hickey, M. B.; Moulton, B.; Perman, J. A.; Peterson, M. L.; Wojtas, Ł.; Almarsson, Ö .; Zaworotko, M. J. Cryst. Growth Des. 2012, 12, 4194−4201. (38) Schultheiss, N.; Newman, A. Cryst. Growth Des. 2009, 9, 2950− 2967. (39) Khan, M.; Enkelmann, V.; Brunklaus, G. J. Am. Chem. Soc. 2010, 132, 5254−5263. (40) Yan, D.; Evans, D. G. Mater. Horiz. 2014, 1, 46−57. (41) Morimoto, M.; Irie, M. J. Am. Chem. Soc. 2010, 132, 14172− 14178. (42) Schultheiss, N.; Newman, A. Cryst. Growth Des. 2009, 9, 2950− 2967. (43) Koshima, H.; Nagano, M.; Asahi, T. J. Am. Chem. Soc. 2005, 127, 2455−2463. (44) Sagade, A. A.; Rao, K. V.; George, S. J.; Datta, A.; Kulkarni, G. U. Chem. Commun. 2013, 49, 5847−5849. (45) Ono, T.; Sugimoto, M.; Hisaeda, Y. J. Am. Chem. Soc. 2015, 137, 9519−9522. (46) Seaton, C. C.; Blagden, N.; Munshi, T.; Scowen, I. J. Chem. Eur. J. 2013, 19, 10663−10671. (47) Wykes, M.; Park, S. K.; Bhattacharyya, S.; Varghese, S.; Kwon, J. E.; Whang, D. R.; Cho, I.; Wannemacher, R.; Lüer, L.; Park, S. Y.; Gierschner, J. J. Phys. Chem. Lett. 2015, 6, 3682−3687. (48) Wouters, J.; Quéré, L., Eds. Pharmaceutical Salts and Co-Crystals; RSC Publishing: Cambridge2011. (49) Brittain, H. G. Cryst. Growth Des. 2011, 11, 2500−2509. (50) Cherukuvada, S.; Bolla, G.; Sikligar, K.; Nangia, A. Cryst. Growth Des. 2013, 13, 1551−1557. (51) Chadha, R.; Saini, A.; Khullar, S.; Jain, D. S.; Mandal, S. K.; Guru Row, T. N. Cryst. Growth Des. 2013, 13, 858−870. (52) Goswami, P. K.; Thaimattam, R.; Ramanan, A. Cryst. Growth Des. 2016, 16, 1268−1281. (53) Grifasi, F.; Chierotti, M. R.; Gaglioti, K.; Gobetto, R.; Maini, L.; Braga, D.; Dichiarante, E.; Curzi, M. Cryst. Growth Des. 2015, 15, 1939−1948. (54) Sangtani, E.; Sahu, S. K.; Thorat, S. H.; Gawade, R. L.; Jha, K. K.; Munshi, P.; Gonnade, R. G. Cryst. Growth Des. 2015, 15, 5858− 5872. (55) Tothadi, S.; Sanphui, P.; Desiraju, G. R. Cryst. Growth Des. 2014, 14, 5293−5302. (56) Sanphui, P.; Devi, V. K.; Clara, D.; Malviya, N.; Ganguly, S.; Desiraju, G. R. Mol. Pharmaceutics 2015, 12, 1615−1622. (57) Boese, R.; Bläser, D.; Jansen, G. J. Am. Chem. Soc. 2009, 131, 2104−2106. (58) Nayak, M.; Koner, R.; Lin, H.-H.; Flörke, U.; Wei, H.-H.; Mohanta, S. Inorg. Chem. 2006, 45, 10764−10773. (59) Hazra, S.; Koner, R.; Nayak, M.; Sparkes, H. A.; Howard, J. A. K.; Mohanta, S. Cryst. Growth Des. 2009, 9, 3603−3608. (60) Hazra, S.; Sasmal, S.; Nayak, M.; Sparkes, H. A.; Howard, J. A. K.; Mohanta, S. CrystEngComm 2010, 12, 470−477. (61) Nayak, M.; Jana, A.; Fleck, M.; Hazra, S.; Mohanta, S. CrystEngComm 2010, 12, 1416−1421. (62) Sasmal, S.; Majumder, S.; Hazra, S.; Sparkes, H. A.; Howard, J. A. K.; Nayak, M.; Mohanta, S. CrystEngComm 2010, 12, 4131−4140. (63) Nayak, M.; Hazra, S.; Lemoine, P.; Koner, R.; Lucas, C. R.; Mohanta, S. Polyhedron 2008, 27, 1201−1213. (64) Aznan, A. M. A.; Safwan, A. P.; Abdullah, Z.; Kaulgud, T.; Arman, H. D.; Mahindaratne, M.; McNeil, L. E.; Tiekink, E. R. T. Cryst. Growth Des. 2014, 14, 5794−5800. M



Article

(96) Biswas, A.; Ghosh, M.; Lemoine, P.; Sarkar, S.; Hazra, S.; Mohanta, S. Eur. J. Inorg. Chem. 2010, 2010, 3125−3134. (97) Sasmal, S.; Hazra, S.; Sarkar, S.; Mohanta, S. J. Coord. Chem. 2010, 63, 1666−1677. (98) Majumder, S.; Koner, R.; Lemoine, P.; Nayak, M.; Ghosh, M.; Hazra, S.; Lucas, C. R.; Mohanta, S. Eur. J. Inorg. Chem. 2009, 2009, 3447−3457. (99) Biswas, A.; Mandal, L.; Mondal, S.; Lucas, C. R.; Mohanta, S. CrystEngComm 2013, 15, 5888−5897. (100) Chakraborty, P.; Jana, A.; Mohanta, S. Polyhedron 2014, 77, 39−46. (101) Zamian, J. R.; Dockal, E. R.; Castellano, G.; Oliva, G. Polyhedron 1995, 14, 2411−2418. (102) Correia, I.; Pessoa, J. C.; Duarte, M. T.; da Piedade, M. F. M.; Jackush, T.; Kiss, T.; Castro, M. M. C. A.; Geraldes, C. F. G. C.; Avecilla, F. Eur. J. Inorg. Chem. 2005, 2005, 732−744. (103) Bermejo, M. R.; Fernández, M. I.; Gómez-Fórneas, E.; González-Noya, A.; Maneiro, M.; Pedrido, R.; Rodríguez, M. J. Eur. J. Inorg. Chem. 2007, 2007, 3789−3797. (104) Cunningham, D.; Gilligan, K.; Hannon, M.; Kelly, C.; McArdle, P.; O’Malley, A. Organometallics 2004, 23, 984−994. (105) APEX2, SMART, SAINT & SADABS; Bruker, AXS Inc.: Madison, Wisconsin, USA, 2012. (106) Sheldrick, G. M. Acta Crystallogr., Sect. C: Struct. Chem. 2015, 71, 3−8. (107) Farrugia, L. J. J. Appl. Crystallogr. 2012, 45, 849−854. (108) van der Sluis, P.; Spek, A. L. Acta Crystallogr., Sect. A: Found. Crystallogr. 1990, 46, 194−201. (109) Spek, A. L. J. Appl. Crystallogr. 2003, 36, 7−13. (110) Addison, A. W.; Rao, T. N.; Reedijk, J.; van Rijn, J.; Verschoor, G. C. J. Chem. Soc., Dalton Trans. 1984, 1349−1356. (111) Hazra, S.; Guedes da Silva, M. F. C.; Karmakar, A.; Pombeiro, A. J. L. RSC Adv. 2015, 5, 28070−28079.

N


IV) Salts, Cocrystals, and Salt

Recommend Documents